Consumers use tissue products for a wide variety of applications. For example, various types of tissue products may be used, such as facial tissues, bath tissues, paper towels, napkins, wipes, etc. In many instances, various types of liquid-based compositions, such as softening compositions, lotions, friction reducing agents, adhesives, strength agents, etc., are also applied to one or paper webs of the tissue product. For example, a paper web is often softened through the application of a chemical additive (i.e., softener). However, one problem associated with some liquid-based compositions is the relative difficulty in uniformly applying the composition to the paper web of the tissue product. Moreover, many application methods are relatively inefficient and thus may result in substantial waste of the composition being applied.
For instance, many softeners are made as an emulsion containing a particular solids content in solution. However, such liquid-based compositions are often difficult to adequately apply to a paper web. In particular, when applying such a liquid-based composition, the paper web can become undesirably saturated, thereby requiring the paper web to be dried. Moreover, it is also difficult to uniformly spread the liquid-based composition on a paper web in such a manner to provide adequate surface area coverage. In addition, some softeners contain components that cause the liquid-based composition to be formed as a solid or semi-solid. To facilitate application of these liquid-based compositions onto a tissue product, extensive heating may be required. Moreover, even after extensive heating, it may nevertheless be difficult to uniformly apply the composition to the tissue surface.
As such, a need currently exists for an improved method of applying a liquid-based composition to a paper web.
In accordance with one embodiment of the present invention, a method of applying a foam composition to a paper web having a first surface and an opposing second surface is disclosed. The method comprises forming a paper web from papermaking fibers. The paper web is carried by a first moving papermaking surface (e.g., fabric, wire-mesh surface) so that the first surface of the paper web faces said first moving papermaking surface.
The method also comprises depositing the foam composition onto a second moving papermaking surface (e.g., fabric, wire-mesh surface, etc.). The second moving papermaking surface is positioned adjacent to the first moving papermaking surface so that the second surface of the paper web faces the second moving papermaking surface. As a result, at least a portion of the foam composition is transferred to the paper web.
In one embodiment, the first moving papermaking surface and the second moving papermaking surface can be wrapped around a roll. When wrapped in this manner, the papermaking surfaces can be impressed against the roll to facilitate transfer of the foam composition to the paper web. In some embodiments, the angle of the wrap is from about 90xc2x0 to about 180xc2x0, and in some embodiments, from about 100xc2x0 to about 150xc2x0. Moreover, if desired, the first moving papermaking surface and the second moving papermaking surface can converge at a nip. In some embodiments, for example, the foam composition is applied to the second moving papermaking surface using a foam applicator that is positioned less than about 200 inches, in some embodiments less than about 100 inches, and in some embodiments from about 5 inches to about 60 inches from the nip.
Other features and aspects of the present invention are described in more detail below.